In the early 1900s a gent named Edward S. Curtis realized that some of G. A. Custer's Crow scouts were still living. Curtis set about interviewing those scouts. Crow scouts claimed Custer sat on his horse on Weir Point, watching Reno get his butt kicked, refusing to come to Reno's aid.
Curtis had a big problem, the scouts version of the Little Bighorn battle would fly in the face of the official US Army version and the version being touted in lectures all over the country by Custer's widow, Libby.
For Curtis, the battles pivotal point, as related by the Crows, occurred atop Weir Point. From there, the scouts and Custer watched warriors armed with bows and arrows, firearms and war clubs swarm Reno and his troops. With no reinforcements in sight, Reno halted his command, dismounted and formed a skirmish line. According to the narrative of White Man Runs Him, as recorded by Curtis:
Custer was watching them all this time. I was coaxing Custer to fight, but he said: Let them fight. We will have our chance.
Shortly afterward the scouts departed, released from their duty and advised to save your selves.
Curtis was certain the scouts spoke the truth. At the same time he realized their story belied widely accepted beliefs affixed to Custers defeat: chief among them was that Major Renos betrayal of Custer was prime cause for the debacle. Had Reno pressed an aggressive attack as expected of him, Custer would not have been left to wage a desperate struggle. In the Crow accounts, however, Reno was the betrayed and Custer the betrayer. In Notes on Custer Battle and Field, Curtis wrote:
The point I want to make clear is that, according to this evidence, Custer sat on this high point and saw Reno make the mistake of dismounting his troops if it was a mistake; saw the opening of the fight; the men beginning to give way slowly at first, then in confusion and disorder, little groups here and there making their own stubborn fight without a commander to properly direct them, men trying to pick up wounded comrades, trying to drag them to concealment in the brush; saw and must have known that Reno had lost control of his command
watched all of this from 45 to 60 minutes
and that whole fight was so close to him that he could have been in the thick of it in five minutes
had he got to the aid of Reno, the Sioux would have been routed in half an hour, without doubt.
Curtis went to US president T. Roosevelt who asked him not to write the scouts eyewitness accounts of the Little Bighorn battle. Curtis obeyed.
The Curtis notes became available in the 1990s. http://nativeamericanencyclopedia.com/goes-ahead/